Study and analysis of switching transients in high voltage transmission line

Abstract

A switching transient over-voltage is created and travels along the line following switching to energize or de-energize a transmission line. This switching transient over-voltage will reach its highest levels at the transition points connecting an underground cable to an overhead line. The transient over-voltage will exceed the normal operating voltage and will be transmitted to the lower voltage level system. The magnitude of the transient over-voltage has to be limited to avoid exceeding substation equipment surge ratings. Without the limitation, the overvoltage may cause damage to the system protective devices. This study will investigate transient over-voltages associated with closing a breaker to energize or de-energize a high voltage transmission line.